Michael Rosenbaum is leaving the CW's "Smallville" after seven seasons with the show. Rosenbaum, who plays Superman's nemesis Lex Luthor, will be replaced by two new villains.

"It is time for me to start the next chapter of my life and career," Rosenbaum said Thursday. "I hope that I gave you some enjoyment over the years and that you found my portrayal of Lex Luthor to be satisfying."

A statement from "Smallville's" executive producers hinted that Rosenbaum might appear as a guest in the upcoming eighth season.

"While Michael won't be a series regular and we won't have the pleasure of working with him on a weekly basis this fall, we like to think that we haven't seen the last of Lex Luthor," it said.

Rosenbaum's departure had been rumored since producers have been looking for ways to shake up the series and create new challenges for Superman in what might be the show's final season.

One of the new villains is Doomsday, who's notable for killing Superman in the DC Comics Superman universe. Another is a female villain producers describe as "intelligent, brilliantly manipulative and dangerously sinister" whose "attraction with Clark may prove to be as deadly as kryptonite for him."